色散对相位调制器产生毫米波传输的影响

The Impact on Optical Millimeter Wave Distribution Generated by Phase Modulator

分析了光纤中色度色散对利用单个相位调制器产生的毫米波的影响,并进行了计算机仿真分析。对比了经过普通单模光纤中不同距离传输后,光波在接收端拍频时产生毫米波的波形和电谱图。仿真结果表明,色散虽然不改变传输信号的光谱结构,但它能够改变不同频率谱线的相位,因此,可以通过拍频产生不同频率的毫米波信号。在调制指数一定的情况下,信号的电谱图与传输距离、光纤的二阶色散和相位调制器上所加微波信号的频率密切相关,而增加调制指数可以提高高次谐波的功率。

The impact of chromatic dispersion on the generation of the optical millimeter wave by single modulator is analyzed,and simulation results are shown.Then we compare the waveform diagrams and the electrical spectrum diagrams of optical millimeter wave which are generated at the receiver after different distances transmission.The simulation results show that the dispersion does not alter the optical spectrum structure of signal in transmission,but it changes the phases of spectrum lines with different frequencies,so the harmonic millimeter waves are generated by beating.Given a modulation index,electrical spectrum diagram of signal depends on the transmission distance,the second order dispersion of fiber and driven frequency in the phase modulator,and the increasing of modulation index can enlarge the power of higher order harmonic millimeter wave.